Hi.i understand that you might be meaning that your daughter has a constipation problem.Good toilet training is very important for solving these kind of issues. Good nutrition is also very important.
Remember that you cannot force your child to potty train.Try potty training when you have a consistent routine.You set up a routine everyday without major changes.Talk to your child about nappy changes and also assign the bathroom for any changes that you do so that she understands that this is the room that she has to go to in case she has to go for potty.
Leave the potty where she can see it and explain to her what it is for.If you have a older child let her observe her because they learn faster by observing someone else do the same.
Let her sit on the potty immediately after a meal.Giving a toy or a book when she is using the potty helps them to stay occupied and not become restless.
I would definitely suggest talking to your paediatrician about it in detail as this can be a very challenging topic for you.
Hope this helps little